Not applicable.
1. Field of Invention
This invention relates to machine input interface, specifically to an optical method and apparatus for entering information into machines, such as computers.
2. Description of Prior Art
Many types of input devices have been developed to provide some means for entering information into machines, especially computers, data processing and information systems. Typical input devices include keyboard, keypad, mouse, track ball, joystick, Light pen, touch pad, touch screen, pen tablet, data tablet, remote control, etc. However, despite the effort of ergonomic designs and the use of wireless transmission mode for mouse pad and keyboard etc., the number of the cases of computer related Repetitive Strain Injury (RSI) is still increasing at about 700,000 per year in the U.S. When a person is injured of this cause, the use of such input devices is then restricted and the productivity is lowered. In some worst cases, a change of career is pursued.
Anyone who works at a computer is at risk for developing RSI regardless of what type of input devices listed above is used even with conventional improvement, because the factors that predispose someone to injury exist in the usage of all the devices listed above. These factors include:
(1). Repetitive movements and exertion of force from hand and fingers on a hard surface. The force of the movement is a particular factor of RSI. For example, the usage of a keyboard requires repetitive hits on keys using the fingers, which may result in tons of pressures on a finger each day.
(2). Working in a fixed position for a long period of time. This may pinch nerve groups and retard the blood circulation of the body. As all the devices listed above require fixed postures in using them, even the best ergonomically designed devices do not prevent the user from injury of this kind.
(3). Improper postures, such as bending the wrists to the side, are common for most people whose shoulders are wider than the key range. However, the perfect postures for the fingers, wrists, arms, and back require enormous effort to maintain and usually cannot last very long.
(4). Improper workstation configuration strains different areas of the body from neck to wrists. In reality, it is impossible to get a perfectly fit configuration for any specific person.
Besides the injuries that they may cause people, the conventional devices on the market also have following disadvantages:
(1). Devices that contain buttons, keys, or balls which need to be moved by forces from outside of the system usually cannot be sealed or covered. They are often contaminated by dirt and other materials and become malfunctioning.
(2). Buttons and keys usually have size limit as imposed by human hands and fingers. For instance, all character keys cannot be installed at a proper size on a cell phone set. The size of the keyboard is also a limiting factor to prevent the notebook computers from becoming smaller.
In this invention, the optical machine input interface comprises a light source and a receiving module. The light source emits a narrow and directional beam of photons, such as a laser pointer and can be operated easily by hand. The receiving module comprises a collection of photodetectors with associated amplifiers and a decision circuit. The impact of the light beam on a photodetector generates a corresponding signal that is further processed and transmitted by the circuit to the system. Each entry of a photodetector represents a command or data. Thus, commands and data can be entered into the system by shinning the light beam at different photodetector entries.
In operation, the operator manually operates the light source to point at different photodetectors for entering commands and data. In one embodiment for example, each key on a computer keyboard is replaced by a photodetector entry. The same signal is sent to the computer interface upon the impact of the light beam at a photodetector entry just as the corresponding key is pressed. The operator can hold a laser pointer in hand and point at the photodetector entries one at a time to enter commands and data into the system.
It is accordingly an object of this invention to provide an input interface that can be used by people who cannot use a keyboard and a mouse and who are restricted from the use of those for the suffering from RSI. It is also an object to minimize the possibilities of injuries usually caused by working on the prior art. In particular, for the task of data entry, the objects and advantages of this invention are:
(a) to reduce the forceful movement of hands and arms of the operators
(b) to free the operators from applying pressure on fingers and wrists
(c) to free the operators from the need of maintaining a fixed position and posture
(d) to free the operator from the need of staying close to the surface where the electrical signals are generated.
(e) to enable those who are restricted by physical conditions from using the keyboard and mouse to work with computers.
Further objects and advantages are to provide a machine input interface of which the receiving module and the receiving entries can have a much wider range of possible sizes; the circuit can be sealed and free from contamination of outside materials such as dust and fluid; and the moving parts can be separated from the system. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.